A computer implemented method for providing feedback of harmonic content relating to a music track, includes receiving music track information; generating harmonic music track parameters based on the received music track information; displaying notation information for a user for performing the music track at a given time for the music track based on the harmonic music track parameters; receiving harmonic user content generated by an instrument performed by the user, using at least one capturing device; generating real-time performance feedback for the user based on comparison of the harmonic user content and the harmonic music track parameters according to predefined settings; receiving reference harmonic user content from a plurality of reference users over a public network; adjusting, based on the reference harmonic user content, at least one of the following: the predefined settings; and the harmonic music track parameters.